Re: [PATCH v8 4/5] IMA: Add support to limit measuring keys

From: Mimi Zohar
Date: Wed Nov 20 2019 - 19:53:42 EST

On Wed, 2019-11-20 at 16:03 -0800, Lakshmi Ramasubramanian wrote:
> On 11/20/2019 3:19 PM, Mimi Zohar wrote:
> Hi Mimi,
> >> The above can be used to correlate the key measurement IMA entry,
> >> ima-sig and ima-modsig entries using the same key.
> >
> > True, but associating the public key measurement with the file
> > signature requires information from the certificate (e.g. issuer,
> > serial number, and/or subject, subject keyid).
> >
> > For a regression test, it would be nice if the key measurement,
> > itself, contained everything needed in order to validate the file
> > signatures in the measurement list.
> I am just trying to understand your asks - Please clarify:
> 1, My change includes only the public key and not the entire certificate
> information in the measured buffer.
> Should I update this current patch set to measure the entire cert. Or,
> can that be done as a separate patch set?
> 2, Should a regression test be part of this patch set for the key
> measurement changes to be accepted?

Once the key measurement is defined and upstreamed, changing it would
result in a regression. ÂIf we think that it would change multiple
times, then perhaps the buffer measurement needs to contain some sort
of versioning.

I would very much like for a regression test to be included in this
patch set, but it isn't a requirement, as long as everything needed
for verifying a signature is included in the key measurement.